This invention relates generally to the providing or supplying of inflation gas. More particularly, the invention relates to assemblies for providing or supplying an inflation gas such as may be desired for certain inflatable passive restraint systems for use in vehicles for restraining the movement of an occupant in the event of a vehicular collision as well as methods of forming or making such inflator assemblies.
It is well known to protect a vehicle occupant by means of safety restraint systems which self-actuate from an undeployed to a deployed state without the need for intervention by the operator, i.e., “passive restraint systems.” Such systems commonly contain or include an inflatable vehicle occupant restraint or element, such as in the form of a cushion or bag, commonly referred to as an “airbag cushion.” In practice, such airbag cushions are typically designed to inflate or expand with gas when the vehicle encounters a sudden deceleration, such as in the event of a collision. Such airbag cushions may desirably deploy into one or more locations within the vehicle between the occupant and certain parts of the vehicle interior, such as the doors, steering wheel, instrument panel or the like, to prevent or avoid the occupant from forcibly striking such parts of the vehicle interior. For example, typical or customary vehicular airbag cushion installation locations have included in the steering wheel, in the dashboard on the passenger side of a car, along the roof line of a vehicle such as above a vehicle door, and in the vehicle seat such as in the case of a seat-mounted airbag cushion. Other airbag cushions such as in the form of knee bolsters and overhead airbags also operate to protect other or particular various parts of the body from collision.
In addition to one or more airbag cushions, inflatable passive restraint system installations also typically include a gas generator, also commonly referred to as an “inflator.” Upon actuation, such an inflator device desirably serves to provide an inflation fluid, typically in the form of a gas, used to inflate an associated airbag cushion. Various types or forms of inflator devices have been disclosed in the art for use in inflating an inflatable restraint system airbag cushion.
One particularly common type or form of inflator device used in inflatable passive restraint systems is commonly referred to as a pyrotechnic inflator. In such inflator devices, gas used in the inflation of an associated inflatable element is derived from the combustion of a pyrotechnic gas generating material.
Typically, pyrotechnic inflators include a pressure vessel housing so as to be able to withstand the 10 MPa to 30 MPa internal pressures created during combustion of the pyrotechnic gas generating material contained within the inflator. In practice, such pressure vessels are commonly made by welding together two or more metal, e.g., steel or aluminum, components after the loading therein of the inflator internal contents, such as the pyrotechnic gas generating material, for example.
The automotive industry, however, continues to seek inflatable restraint systems that are smaller, lighter, and less expensive to manufacture. As industry constraints regarding factors such as the weight and size of vehicle components continue to evolve, corresponding changes to associated inflatable restraint systems are desired and required in order to better satisfy such constraints.